Glossary
6023E/6024E/6025EUser Manual G-4 ni.com
DAQ data acquisition—(1) collecting andmeasuring electrical signals from
sensors, transducers, and test probes or fixtures and processing the
measurementdata using a computer; (2) collecting and measuring the same
kinds of electrical signals with A/D and/or DIO boards plugged into a
computer,and possibly generating control si gnals with D/A and/or DIO
boards in thesame com puter
dB decibel—the unit for expressing a logarithmic measure of the ratio of two
signal levels:dB=20log10 V1/V2, for signals in volts
DC direct current
DGND digital ground signal
DIFF differentialinput configuration
differentialamplifier anamplifier with two input terminals, neither of which are tied to a ground
reference, whose voltagedifference is amplified
differentialinput the two-terminal input to a differential amplifier
DIO digitalinput/output
dithering theaddition of Gaussian noise to an analog input signal
DMA directmemory access—amethod by which data can be transferred to/from
computer memory from/to a deviceo r memory on the buswhile the
processor does something else. DMA is the fastest method of transferring
data to/from computer memory.
DNL differential nonlinearity—a measure in LSB of the worst-case deviation of
code widths from their ideal valueof 1 LSB
DO digital output
drivers/driversoftware softwarethat controls a specific hardware device such as a DAQ device
E
EEPROM electricallyerasable programmable read-only memory—ROM that can be
erased with an electricalsignal and reprogrammed. Some SCXI modules
contain an EEPROMto store measurement-correction coefficients.